I am using Outlook 2003 with ZCO 5.12, and I have a couple of users who do not have the same calendar sharing in Outlook and in the webmail.

For instance, in the webmail, User A, will have an access to User B and C shared calendar (which is fine).
But in Outlook, the same user will have access to User B (fine) but also User D calendar (which was never supposed to happen).

I removed the account .zdb and .idm files used by Outlook to resync from a fresh copy, but the problem still happens...

My question1: how can a do a fresh sync? (I am assuming the Zimbra account is correct, and that the (corrupted) ZCO calendar sharing info is stored somewhere on the PC). Apparently deleting the account.zdb is not enough.

My question 2: In case the calendar sharing information on the Zimbra server is corrupted, how can I view this (and correct it)?

Not sure which .zdb files you removed, but for each delegate store (shared calendar) you get a different .zdb. For example, if your profile is Zimbra.zdb, when you open a shared folder, that one will be Zimbra1.zdb, the next Zimbra2.zdb, etc. So you have to delete the right one.

The easiest way to get an initial sync of the delegate store is to close that store in Outlook, and then do Open Other User's Mailbox on it. That will initial sync it.

When you say the user has access to user D calendar in Outlook, can the user in Outlook actually see the user D calendar and make changes to it?

I'm not sure of a way in the UI to see all the shares done on the server. If you do an initial sync in Outlook with ZCO logging on, I could tell.

Version 6.0 of ZCO will have improvements in sharing where you will be able to see this stuff.